A. Field of the Invention
The present invention relates to a commercial apparatus for fast freezing food products, and more specifically to commercial freezers using interior helical conveyors. The present apparatus consists of room having a helical belt upon which the food is placed and which has chilled air drawn horizontally across the food in a uniform manner.
B. Description of the Related Art
Refrigeration of food products in order to preserve them has been artificially accomplished for a number of years. An Information Disclosure Statement has been submitted conforming to 37 C.F.R. .sctn..sctn. 1.97 and 1.98. Of the art disclosed therein, the following three U.S. patents are considered to be relevant: U.S. Pat. No. 3,391,548 issued to Gram on Jul 9, 1968; U.S. Pat. No. 4,103,768 issued to Persson on Aug. 1, 1978; and U.S. Pat. No. 4,798,062 issued to Lipinski et al. on Jan. 17, 1989.
The Gram patent discloses a helical refrigeration apparatus in conjunction with a means for moving articles through the refrigerated area. The Gram patent does not disclose a refrigeration apparatus in and of itself.
The Persson patent discloses a helically curved conveyor for use in an enclosure that may refrigerate articles. Persson has treating machinery within an area surrounded by the conveyor, with simple means for circulating air.
The Lipinski et al. patent discloses a portable food freezer, with the path of the air blown by the fan inside the freezer is not optimized and allows some articles to be cooled with air previously heated by other articles.
The related art is believed not to disclose means by which articles travelling within a freezer may be uniformly cooled in the manner disclosed herein. In freezers, air used for cooling is used to cool several articles before being again refrigerated by cooling coils or the like. For a given volume of air, the first article cooled by the refrigerated air enjoys the lowest temperature. Heat given off by the first article is absorbed by the passing air, warming the air. Articles succeeding the first article cooled have air passed over them that has been warmed by an earlier article. As a result articles cooled later by that same air are not cooled to the same degree as the first article.
When all articles to be cooled are subjected to the same cold temperature, the articles may be cooled more uniformly. Quick and uniform cooling enhances refrigeration and better preserves those articles being refrigerated. At the same time, it improves the freezing efficiency of the unit, and reduces the level of product dehydration associated with mechanical spiral freezers.
Quick cooling can be achieved by circulating air across the tops of articles to be cooled. The flow of air across the tops of articles to be cooled is in contrast with most helical refrigerators that move air generally across the sides of articles to be cooled in a vertical direction.